Roof-nosed tuyere



F. C. DIAZ ROOF-NOSED TUYERE March 21, 1950 Fild Feb. 13, 1948 FIELD INVENTOR. F1079 0/42,

' Patented Mar. 21, 1950 ROOF-NOSED TUYE'RE Floyd 0. Dial, Charlerol, Pa., assignor to The American Steel and Wire Company of New Jersey, a corporation of New Jersey Application February 13, 1948, Serial No. 8,169

2 Claims.

This invention relates to tuyeres and more particularly to blast-furnace tuyeres which are used to conduct pre-heated air or blast into a blast-furnace.

As is commonly known among blast-furnace operators, regardless of what type fuel is used. combustion or fusion takes place in the hearth of the furnace not more than about 35 inches beyond the nose of the tuyre. The fusion zone then extends upwards from the level of the tuyres because of the upward pressure of the blast. Regardless 'of how great the pressure of the blast being blown into the furnace, there is a limit to the pressure that can be built up proportionately in the hearth of the furnace below the tuyeres. Heretofore, designers of blast-furnace tuyeres have neglected to take into consideration this low-pressure area which is created on the under side of the tuyere when the blast is introduced into the furnace.

-As the blast leaves the tuyere it is deflected sharply upward and becomes widely diffused. This diffusion takes place gradually as the blast penetrates the stock beyond the nose of the tuyere, the point of highest pressure being at the tuyere nose. In the normal operation of a blastfurnace, iron and cinder percolate down through the stock to the hearth as the weight thereof overcomes the blast pressure. Because of certain chemical and physical conditions of the furnace, furthermore, an accumulation of iron sometimes occurs, which does not penetrate the stock normally but falls suddenly to the hearth. This falling material sometimes drops into the region of fusion almost overcoming the blast pressure, but is deflected enough to miss the top of the nose of the tuyere by the high pressure of the blast present at that point. Below the top of the tuyere, however, the blast pressure falls off sharply so that material coming down so near the tuyere is apt to strike the bottom of the tuyere because of the low-pressure area existing there. The bottom of the tuyere is thus subject to severe abuse and this condition accounts for most of the damage suffered by tuyres during furnace operation. It makes frequent replacement of tuyeres necessary and involves a consequent loss in production.

The principal object of my invention is to provide a blast-furnace tuyere having means for protecting the bottom from damage as described above so that it will have a much longer life.

Another object of my invention is to provide a tuyere with a nose having an overhang or proaffording a roof-like surface protecting the bot- Another object of my invention is to provide a tuyere that will project the blast farther inwardly and shift the point of maximum pressure, thereby protecting the bottom of the tuyere from falling material by deflecting it toward the center of the hearth.

Still another object of my invention is to provide a tuyere having a nose with an extended roof portion of increased thickness designed to withstand more effectively the wear resulting from abrasion by the hot blast.

These and other objects will become more apparent after referring to the following specification and the accompanying drawings, in which:

Figure 1 is a partial vertical section through the hearth and bosh of a blast-furnace having the tuyere of my invention installed therein;

Figure 2 is a central vertical section through the tuyere taken along the plane of line II-II of Figure 3;

Figure 3 is an elevation of the tuyre looking toward the nose; and

Figure 4 is an elevation of the rear end of the tuyere.

Referring in detail to the drawings, Figure 1 shows a blast-furnace l0 supported on a plurality of columns H and including a bosh l2, and a hearth it! having tuyres l4 installed therein subjacent the lower bosh line. Hot blast is supplied to-the tuyeres from a bustle pipe l5 through tuyere stocks l6 and below pipes ll. This construction is conventional except for the novel tuyere of my invention, the details of which will now be described. 7

Referring more particularly to Figures 2 through 4, my improved tuyere l4 has the usual central air passage l8 therethrough. The nose or discharge end l9 has an overhang or pro jecting roof 20 extending around the upper portion thereof. As shown, the roof projects a substantial distance beyond the bottom of the nose designated 2|. The tuyre is generally frustoconical in shape having spaced inner and outer walls providing a cooling chamber 22. The cooling chamber extends in its upper portion into the roof of tuyere It. The fluid coolant is introduced through an inlet 23 into a passage defined by spaced parallel ribs terminating adjacent the nose so that the incoming water is directed to the roof portion of the tuyere. An outlet for the cooling chamber is provided at 24. Openings 25 and 26, which may be plugged or Jeotion extending around the upper portion and 5 opened, are provided so that they can be used In order to further insure the tuyere a long life, the thickness 0! top wall 21 of the roof portion 20 is made greater than that of the walls of the tuyere body.

In operation, roof 20 of tuyere i4 functions to advance the high-pressure point of the blast entering the furnace a substantial distance beyond the high-pressure point of known tuyeres, thereby extending the fusion zone far enough away from the bottom of the tuyre nose 2| so that the pressure of the blast will deflect away therefrom any failing material, thus: practically eliminating the possibility of damage to the tuyere.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A blast-furnace tuyere comprising a frustoconical body having an air passage therethrough, an overhanging roof portion projecting from said body, said roof portion extending from substantially the center line in a horizontal plane to the top of said body, the top wall of said overhanging roof portion being substantially greater in cross-section than the other walls of said body,

said body having spaced inner and outer walls defining a cooling chamber surrounding said air passage substantially along its length and ex- 4 tending into said overhanging roof portion, and a longitudinal channel in the upper portion 0! said cooling chamber, said channel extending horizontally toward said overhanging roof portion from an inlet opening in the face of said body opposite said overhanging roof portion.

2. A blast-furnace tuyere comprising a frustoconical body having an air passage therethrough, an undercut bottom portion on the nose of said body extending downwardly and inwardly from substantially the longitudinal center line of said body, the top wall of the nose of said body being substantially greater in cross-section than the other walls of said body, said body having spaced inner and outer walls defining a cooling chamber surrounding said air passage substantially along its length, and a longitudinal channel in the upper portion of said cooling chamber, said channel extending horizontally toward the nose of said body from an inlet opening in the face of said body opposite its nose.

' FLOYD C. DIAZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 205,744 Hartman July 9, 1878 1,873,996 Cunningham Aug. 30, 1932 1,969,693 Fox Aug. '7, 1934 2,394,497 Steudel Feb. 5, 1946 

